1 files changed, 80 insertions, 6 deletions

diff --git a/src/syntax/test.rs b/src/syntax/test.rs
index df354768..6c89b4f5 100644
--- a/src/syntax/test.rs
+++ b/src/syntax/test.rs
@@ -1,8 +1,62 @@
+use std::fmt::Debug;
+
 use super::func::FuncHeader;
 use super::expr::{Expr, Tuple, Object};
+use super::span::{Span, Spanned};
+use super::tokens::Token;
 use super::*;
 
 
+/// Check whether the expected and found results for the given source code
+/// match by the comparison function, and print them out otherwise.
+pub fn check<T>(src: &str, exp: T, found: T, spans: bool)
+where T: Debug + PartialEq + SpanlessEq {
+    let cmp = if spans { PartialEq::eq } else { SpanlessEq::spanless_eq };
+    if !cmp(&exp, &found) {
+        println!("source:   {:?}", src);
+        println!("expected: {:#?}", exp);
+        println!("found:    {:#?}", found);
+        panic!("test failed");
+    }
+}
+
+/// Create a vector of optionally spanned expressions from a list description.
+///
+/// # Examples
+/// When you want to add span information to the items, the format is as
+/// follows.
+/// ```
+/// spanned![(0:0, 0:5, "hello"), (0:5, 0:3, "world")]
+/// ```
+/// The span information can simply be omitted to create a vector with items
+/// that are spanned with dummy zero spans.
+macro_rules! spanned {
+    (item ($sl:tt:$sc:tt, $el:tt:$ec:tt, $v:expr)) => ({
+        #[allow(unused_imports)]
+        use $crate::syntax::span::{Position, Span, Spanned};
+        Spanned {
+            span: Span::new(
+                Position::new($sl, $sc),
+                Position::new($el, $ec)
+            ),
+            v: $v
+        }
+    });
+
+    (vec $(($sl:tt:$sc:tt, $el:tt:$ec:tt, $v:expr)),* $(,)?) => {
+        (vec![$(spanned![item ($sl:$sc, $el:$ec, $v)]),*], true)
+    };
+
+    (vec $($v:expr),* $(,)?) => {
+        (vec![$($crate::syntax::test::zspan($v)),*], false)
+    };
+}
+
+/// Span an element with a zero span.
+pub fn zspan<T>(v: T) -> Spanned<T> {
+    Spanned { v, span: Span::ZERO }
+}
+
 function! {
     /// Most functions in the tests are parsed into the debug function for easy
     /// inspection of arguments and body.
@@ -30,26 +84,31 @@ pub trait SpanlessEq<Rhs=Self> {
     fn spanless_eq(&self, other: &Rhs) -> bool;
 }
 
-impl SpanlessEq for Vec<Spanned<Token<'_>>> {
-    fn spanless_eq(&self, other: &Vec<Spanned<Token>>) -> bool {
+impl<T: SpanlessEq> SpanlessEq for Vec<Spanned<T>> {
+    fn spanless_eq(&self, other: &Vec<Spanned<T>>) -> bool {
         self.len() == other.len()
-        && self.iter().zip(other).all(|(x, y)| x.v == y.v)
+        && self.iter().zip(other).all(|(x, y)| x.v.spanless_eq(&y.v))
     }
 }
 
 impl SpanlessEq for SyntaxModel {
     fn spanless_eq(&self, other: &SyntaxModel) -> bool {
+        self.nodes.spanless_eq(&other.nodes)
+    }
+}
+
+impl SpanlessEq for Node {
+    fn spanless_eq(&self, other: &Node) -> bool {
         fn downcast<'a>(func: &'a (dyn Model + 'static)) -> &'a DebugFn {
             func.downcast::<DebugFn>().expect("not a debug fn")
         }
 
-        self.nodes.len() == other.nodes.len()
-        && self.nodes.iter().zip(&other.nodes).all(|(x, y)| match (&x.v, &y.v) {
+        match (self, other) {
             (Node::Model(a), Node::Model(b)) => {
                 downcast(a.as_ref()).spanless_eq(downcast(b.as_ref()))
             }
             (a, b) => a == b,
-        })
+        }
     }
 }
 
@@ -86,3 +145,18 @@ impl SpanlessEq for Object {
             .all(|(x, y)| x.key.v == y.key.v && x.value.v.spanless_eq(&y.value.v))
     }
 }
+
+/// Implement `SpanlessEq` by just forwarding to `PartialEq`.
+macro_rules! forward {
+    ($type:ty) => {
+        impl SpanlessEq for $type {
+            fn spanless_eq(&self, other: &$type) -> bool {
+                self == other
+            }
+        }
+    };
+}
+
+forward!(String);
+forward!(Token<'_>);
+forward!(Decoration);